Circuit breaker panel assembly



Nov. 16, 1965 I R. T. CASEY 3,218,520

CIRCUIT BREAKER PANEL ASSEMBLY Filed March 14, 1963 2 Sheets-Sheet 1 //v VENTOR.

Nov. 16, 1965 R. 1: CASEY CIRCUIT BREAKER PANEL ASSEMBLY 2 Sheets-Sheet 2 Filed March 14, 1963 United States Patent 3,218,520 CIRCUIT BREAKER PANEL ASSEMBLY Robert T. Casey, Southington, C0nn., assignor to General Electric Company, a corporation of New York Filed Mar. 14, 1963, Ser. No. 265,143 11 Claims. (Cl. 317-419) The present invention relates to electric circuit breaker panel assemblies and more particularly to such panel assemblies which include means for preventing the unauthorized exchanging or interchanging of circuit breakers in such assemblies.

Electric circuit breaker panel assemblies of the type described are commonly used for the protection of branch circuits in residential and commercial buildings. For adequate protection of such branch circuits, it is necessary that each such circuit have associated with it a circuit breaker of an ampere rating corresponding to the capacity of the wiring used in the circuit. For additional safety, it is required that such panel assemblies include means for preventing the user from removing a given circuit breaker and substituting therefor a circuit breaker of higher ampere rating.

One means for providing such additional protection, in accordance with the prior art, has been to provide a locking means or locking bar which locks all such circuit breakers in place and which can be removed only by partial disassembly of the panel, thus discouraging the user from making such undesired substitutions. A panel as sembly of this type is shown, for example, in copending application Serial No. 108,440, filed May 8, 1961, by Robert E. Bristol and assigned to the same assignee as the present invention.

The use of such locking bar type systems, however, has the disadvantage that in order to install the breakers initially, or to add an additional breaker at some later time, even by authorized personnel, it is necessary to remove the locking bar.

It is an object of the present invention to provide a circuit breaker panel assembly of the type including means for locking circuit breakers in place, in which circuit breakers may be inserted without removing the aforesaid locking means, but may not thereafter be removed until the locking means is released.

In accordance with the invention in one form, an electric circuit breaker panel assembly is provided including a support and means for mounting and connecting circuit breakers on the support, together with means for locking such circuit breakers on the support. Cooperating means is also provided, carried by the locking means and the circuit breakers whereby the circuit breakers may be snapped into locked position without removing the locking bar, but cannot be removed unless the locking bar is first removed.

In one form of the invention, an electric circuit breaker panel assembly is provided of the type including means for releasably locking circuit breakers to a support including a locking bar, each of the circuit breakers including resilient means which snaps into locking engagement with the aforesaid locking bar when the device is assembled on the panel and from which it cannot be released without removal of the locking bar. In another form of the invention, the locking bar itself includes resiliently deformable portions which are deflected by the circuit breakers when they are installed and which serve to lock the circuit breakers in place until the locking bar is removed.

The invention will be more fully understood from the following detailed description, and its scope will be pointed out in the appended claims.

In the drawings:

FIGURE 1 is a plan view of an electric circuit breaker 3,218,520 Patented Nov. 16, 1965 panel assembly incorporating the invention, the front cover or trim of the enclosing box being removed;

FIGURE 2 is an elevation view, partially in section, of the interior portion of the panel assembly of FIGURE 1, taken generally on the line 2-2 of FIGURE 1;

FIGURE 3 is a fragmentary sectional view of one of the circuit breakers of FIGURE 2, taken substantially on the line 33 of FIGURE 2;

FIGURES 4 and 5 are fragmentary elevation and plan views respectively of another embodiment of the invention;

FIGURE 6 is a fragmentary elevation view of another embodiment of the invention;

FIGURES 7 and 8 are fragmentary views of fourth and fifth embodiments of the invention, respectively; and

FIGURE 9 is a fragmentary view of an alternate method of mounting the locking bar.

In FIGURES 1-3 of the drawings, the invention is shown as incorporated in an electric circuit breaker panel assembly comprising a generally rectangular box-like enclosure 10 having a supporting pan 11 mounted on the back wall thereof by suitable means, not shown. The supporting pan 11 includes a back wall 12 and a pair of outwardly directed side flange portions 13. Each of the flanges 13 includes a row of retaining hooks 19, for a purpose to be described.

A pair of elongated bus bars 14 are supported in insulated relation on the pan 11 by means of upper and lower insulating supporting blocks 15 and 16 respectively. The supporting blocks 15 and 16 extend between the flanges 13 of the pan 11, and are mounted to the back wall 12 by suitable means such as by rivets 17. The block 16 includes recesses or pockets 16A receiving the lower ends of the bus bars 14. The upper ends of the bus bars 14 are supported on the surface of the block 15 and are secured thereto by suitable means such as by screws, not shown, extending from the underside of the block 15 into threaded engagement with the bottom wall of screw-clamp type wire connectors 18. The insulating block 15 includes a centrally positioned offset portion 15A for a purpose to be described. The bus bars 14 include transversely extending connecting strap portions 20 terminating in a row of upstanding contact blade portions 21.

A plurality of electric circuit protective devices, comprising electric circuit breakers 23, are mounted on the support 11 by an integral lug portion 24 extending under one of the retaining lugs 19. The other end of each of the circuit breakers 23 carries a plug-in type socket 25 which extends into engagement with one of the contact blades 21. Each of the circuit breakers 23 includes a generally rectangular insulating casing 26 comprising two complementary halves retained in assembled relation by suitable means such as by rivets 27'. The circuit breaker casings 26 have a corner portion 26A shaped to provide clearance for pivoting about the lugs 19, even though the locking bar 30 is in place. Suitable circuit protecting mechanism, not shown, is housed within the enclosure 23 and adapted to be operated by the manually engageable operating handle 27. A suitable type of mechanism is shown, for example, in Patent No. 2,627,563, W. A. Thomas, assigned to the same assignee as the present invention.

The circuit breakers 23 are made in different current ratings, such as 15, 20, 30, and amperes. All of such different rating breakers are of identical size and mount.- ing provisions, but are clearly marked as to ampere rating.

For the purpose of preventing unauthorized interchange of circuit breakers, locking means is provided including a locking bar 30 extending lengthwise of the panel,

substantially centrally of the pan 11. The bar 3% is retained in a predetermined fixed position by means of tapped holes 31 at each end, which threadedly receive screws 32 which are inserted upwardly from under the supporting blocks and 16 respectively. The locking bar can be removed, therefore, only from the back of the pan 11, the pan 11 having a portion, not shown, cut away to provide access to the heads of the screws 32.

Each of the circuit breakers 23 carries an elongated slidable locking member 33, having its end 34 returnbent at an angle to the remainder of the member to form a detent. The locking member 33 is of generally rectangular frame-like formation and includes portions slidably guided in grooves 35 at each side, see FIGURE 3. The panel assembly is preferably manufactured and sold with the locking bar 30 in place.

In use, the electrician merely inserts circuit breakers 23 in place with the locking member 33 in retracted position, as shown in the left hand portion of FIGURE 2, by hooking the lug portion 24 under the corresponding hook member 19 and rotating the circuit breaker about this engagement into plugged-in engagement with the Contact blade 21. When the breaker is in mounted position, the locking member 33 is slid transversely into locked engagement with the locking bar 30, as shown in the right hand portion of FIGURE 2. Thereafter, it is impossible to remove the circuit breaker 23 without first releasing the locking bar 30. The bar 30 can be released, however, only by access to the back of the pan 11, to get at the head of the screw 32.

In FIGURES 4 and 5, there is shown another embodiment of the invention, including a flat strap-like locking gbar 130 and a circuit breaker 123 having a slidable locking tang 133 which is normally in retracted position, but which can be projected to interlocking position by access through the opening 134 in the top of the casing. Once the locking lug 133 has been projected into locking position, it no longer has any portion accessible through the opening 134, and therefore the breaker 123 cannot be removed until the locking bar 130 has been first removed.

In FIGURE 6 there is shown another embodiment of the invention in which a locking bar 230 is provided generally similar to the bar 30 of the form of FIGURE 2. The circuit breaker 223 includes a generally V-shaped resilient locking clip 233 which is retained on the casing 226 by suitable means such as by a rivet 234. In this form of the invention, as the circuit breaker 223 is rotated into mounted position, the resilient clip 233 is deflected by the locking bar 230 and until the breaker is in fully mounted position, at which time it snaps into engagement with the turned-in lip 230A of the locking bar 230. In this form of the invention, therefore, no positive locking act is required by the installing electrician. The breakers merely snap into locked position and cannot thereafter be removed until the locking bar is first removed.

Referring to the form of the invention shown in FIG- URE 7, the invention is shown as incorporated in an electric circuit breaker panel assembly comprising a supporting pan 311 which is adapted to be mounted within a suitable enclosure, not shown. The support 311 has a pair of electrical bus bars 314 mounted thereon in edgewise relation thereto by suitable means, not shown. A sheet of insulating material 311A overlies the base 11 and lies between the bus bars 314 and base 311. A pair of elongated generally Z-shaped retaining brackets 319 are mounted along either edge of the base 311 by means of screws 319A extending upwardly into threaded engagement with the bar 319 from the underside of the supporting pan 311.

The circuit breaker assembly 323 includes a pair of plug-in type sockets 325, each associated with a cor responding one of the circuit breakers contained in the casing 323. The casing 323 is provided with slots 326A spring 323A.

Since the catches 333 snap into engagement with the Z-shaped locking bars 319, the breaker 323 cannot be removed after initial insertion without first removing at least one of the locking bars 319. This can be done only by access from the back of the supporting plate or pan 311, since the strips 319 are mounted on the base 311 by means of screws extending upwardly into threaded engagement with the bar 319 from the underside of the supporting pan 311.

The forms of the invention shown in FIGURES 1 through 6 have the advantageous characteristic that because of the shaping of the casing and the placement of the interfering member, circuit breakers having similar configuration but omitting the slidable locking member 34, 134, or 234 respectively, may be used. Such breakers may be mounted and removed without interference by the locking bar. This may be desirable, since the highest rating breakers, i.e., 50 amperes are not required by the electrical safety regulations to have means for locking them in place. Thus circuit breakers having SO-ampere rating may, if desired, be used without locking means, since if they are removed, there can be no breaker having a higher ampere rating substituted therefor since such breakers are not available in higher rating. Thus the circuit controlled by such a circuit breaker would be protected at least as well, and in fact, overprotected by any rating smaller than 50 amperes.

In the form of the invention shown in FIGURE 8, a locking bar 530 is provided of relatively thin, resilient material. The bar 530 includes integral resilient finger portions 530A. The circuit breaker 523 includes an integral catch portion 523A.

In use, the circuit breaker 523 is engaged with a retaining hook, not shown, and rotated into mounted position. During such installation, the catch portion 523A engages and deflects one of the fingers 530A, which snaps over the catch 523A, to the position shown. Thereafter, removal of the breaker 523 is not possible until the locking bar 530 is removed.

If desired, circuit breakers having the sarne general configuration as breaker 523 may also be provided, omitting the catch portion 523A, so that such breakers may be inserted and removed without interference by the locking bar 530.

In FIGURE 9, there is shown an alternate method of retaining the locking bar 30 in place on the support 11 of FIGURE 1. In this form, screw 40 are provided at each end of the bar 30 (only one shown), which extend through the insulating blocks 15 and 16 respectively, and into threaded engagement with the pan 11. The screws 30 are provided with special heads in a well-known manner, which permit rotation of the screws by a conventional screwdriver in inserting direction, but do not permit rotation of the screws by a conventional screwdriver, in the opposite direction. For the purpose of permitting removal of the screws 40 by authorized personnel, they are provided with flattened side portions 40A, which permit rotation in a removing direction by means of a special tool, not shown, having a socket closely conforming to the outline of the screw-head 40.

While several specific embodiments of the invention have been shown and described, it will be readily apparent that many modifications thereof can readily be made by those skilled in the art, and I therefore intend,

by the appended claims, to cover all such modifications as fall within the true spirit and scope of the invention.

What I claim as new and desire to secure by Letters Patent of the United States is:

1. An electric control device panel assembly comprising:

(a) a generally planar support having a back surface and a front surface,

(b) at least one electrical bus bar conductor supported on said front surface of said support,

(0) a plurality of electric circuit control devices supported in mounted position on said front surface of said support and each electrically connected to at least one of said bus bars.

(d) a locking bar releasably mounted in a fixed position on said front surface of said support by retaining means, said retaining means comprising means impeding release of said locking bar by access from the front side of said support,

(e) interengaging means carried by each of said devices and said locking bar,

(f) said interengaging means comprising means preventing removal of said devices from said support while said locking bar is in said fixed position but not preventing insertion of said devices into said mounted position while said locking bar is in said fixed position.

2. An electric circuit control device panel assembly comprising:

(a) a generally planar support having a back surface and a front surface,

(b) at least one elongated electrical bus bar supported in insulated relation on said front surface of said support,

(c) a plurality of electric circuit control devices supported in mounted position on said front surface of said support and each electrically connected to said bus bar,

(d) an elongated locking bar carried by said support at the front surface thereof in a predetermined fixed position,

(e) interengaging means carried by each of said control devices and said locking bar,

(f) said interengaging means comprising mean preventing removal of said devices from said support While said locking bar is in said fixed position without preventing insertion of said devices into said mounted position whole said locking bar is in said fixed position, and

(g) releasable means mounting said locking bar at the ends thereof on said support, said releasable means comprising means impeding release of said locking bar by access from the front of said support.

3. An electric control device panel assembly comprising:

(a) a generally planar support having a back surface and a front surface,

(b) at least one electrical bus bar supported in insulated relation on said front surface of said support,

(c) a plurality of electric circuit control devices supported in mounted position on said front surface of said support and each electrically connected to at least one of said bus bars,

((1) an elongated locking bar carried by said support at the front surface thereof in a predetermined fixed position,

(e) interengaging means carried by each of said control devices and said locking bar,

(f) said interengaging means comprising means preventing removal of said devices from said support while said locking bar is in said fixed position without preventing insertion of said devices into said mounted position while said locking bar is in said fixed position, and

(g) means mounting said locking bar on said support,

6 said mounting means being releasable only by access from said back surface of said support.

4. An electric control device panel assembly comprising:

(a) a support,

(b) a plurality of electrical bus bars supported in insulated relation on said support,

(0) a plurality of electric circuit control devices supported on said support and each electrically connected to at least one of said bus bars, each of said control devices including an insulating casing,

(d) a locking bar carried by said support in a predetermined mounted position,

(e) at least some of said control devices including a locking member movable with respect to said casing,

(f) said locking member being movable to a noninterfering position in which said device may be mounted on said support while said locking bar is in said predetermined mounted position,

(g) said looking member also being movable toan interfering position when said device is mounted on said support, said locking member when in said interfering position engaging said locking bar and preventing removal of said device from said support,

(h) means preventing movement of said locking member from said interfering to said non-interfering position while said device is mounted on said support and said locking bar is in said predetermined mounted position, and

(i) means releasably mounting said locking bar to said support, said releasable mounting means comprising means impeding release of said locking bar by access from the front of said support.

5. An electric control device panel assembly comprising:

(a) a support,

(b) at least two parallel spaced electrical bus bars mounted in insulated relation on said support,

(0) at least one electrical control device supported on said support and electrically connected to at least one of said bus bars,

(d) a releasable locking bar supported on said support in a predetermined fixed position icentnally thereof and parallel to said bus bars, said locking bar having an elongated recess therein at the underside thereof,

(e) at least some of said electric control devices having a slidable locking member including a detent portion received in said recess of said elongated locking member after said control device is in mounted position and while said locking bar is in mounted position, said detent being releasable only by releasing said locking bar, and

(f) means retaining said locking bar in said position on said support, said retaining means comprising means impeding release of said locking bar by access from the front of said support.

6. An electric circuit control device panel assembly comprising:

(a) a support,

(b) at least two electrical conducting bus bars mounted in spaced apart relation on said support, (c) an elongated locking bar mounted in a predetermined fiXed position on said support,

(d) at least one electric circuit control device supported in mounted position on said support and electrically connected to at least one of said bus bars,

said circuit control device including an insulating in said non-locking position having a portion accessible for moving said locking member from said nonlocking to said locking position, said locking member when in said locking position having no portion thereof accessible for movement of said locking member from said locking to said non-locking position, and

(f) means releasably retaining said locking bar in said position on said base, said retaining means comprising means impeding release of aid locking bar by fixed position on said support,

(e) a pair of elongated rigid locking members carried by said support adjacent said end portions of said device,

(f) said resilient locking members being spaced apart a distance slightly greater than the spacing of said rigid locking members and each having a first locking position and a second non-locking position, means carried by said device biasing each of said locking members from said non-locking to said locking position, each of said elongated rigid locking members access from the front of said panel assembly. 10 of said support and moving said resilient locking 7. An electric circuit controlling device panel assembly member from said locking to said non-locking posicomprising: tion as said device is mounted on said support, said (a) a support, biasing means moving said locking member from said (b) at least two electrical bus bars supported in innon-locking to said locking position when said device sulated relation on said support, is in mounted position on said support,

(0) at least one electrical control device mounted on (g) at least one of said elongated rigid locking memsaid support and electrically connected to at least hers being releasably mounted on said support by one of said bus bars, retaining means releasable by access from a direction (d) a locking member mounted in a predetermined other than the front of said support.

10. An electric circuit control device panel assembly (e) said electrical control device including a locking projection, means mounting said locking projection on said device for movement from a locking position as set forth in claim 9 wherein said one elongated locking means is mounted on said support by means accessible for release only from the back of said support.

(c) at least one electrical control device mounted on said support and electrically connected to at least one of said bus bars,

(d) an elongated locking bar supported on said support to a non-locking position, means biasing said projeC- 11. An electric circuit control device panel assembly tion toward said locking position at all times, said comprising: projection engaging aid locking member when said (a) a support, locking member is in said predetermined position as (b) at least one elongated bus bar conductor mounted said device is mounted on said support and being dein insulated relation on said support, flected thereby, said biasing means moving said pro- (c) an elongated locking bar mounted on said support jection into interlocking relation with said locking in a predetermined fixed position, member when said device is mounted on said support, (d) at least one electrical control device mounted on said projection being substantially inaccessible for said support, said control device including a plug-in movement away from said locking position when said type electrical connecting means electrically condevice is mounted on said support and said locking nected to a portion of said electrical bus bar, member is in said predetermined position, and (e) said control device including a resiliently deform- (f) means retaining said locking bar in said position able locking projection cooperating with a portion on said support, said retaining means comprising of said locking bar to prevent removal of said elecuneans impeding release of said locking bar by access trical control device from said panel without first from the front of said support. removing said locking bar, 8. An electric circuit controlling device panel assem- (f) id l ki oj tio f i Control d i bly comprising: ing and being deflected by a portion of said locking a pp bar and snapping into interlocked engagement with least tW10 electrical bus bars Supported in illsllsaid locking bar when said bar is in said fixed posilated relation on Said pp tion as said electrical control device is moved into plug-in engagement with said portion of said bus bar, and

(g) means releasably retaining said locking bar in said fixed position on said support, said retaining means in a predetermined fixed position, (e) said locking bar including integral resiliently deformable locking portions, (f) said control device including an integral rigid locking projection, said control device and said support being disposed and arranged so that as said control 5 being releasable only by access from a direction other than from the front of said support.

References Cited by the Examiner UNITED STATES PATENTS device is moved to said mounted position said in- 211,189 1/1879 shwarz 292 80 tegral projection of said control device engages and 785,380 3/1905 Rlpsondeflects at least one of said resiliently deformable 11291745 2/1915 portions of said locking bar, whereby said circuit 8/1925 Wlley 292430 breaker is retained in mounted position and cannot 1,558,855 10/,1'925 Field 211 26 be removed until after removal of said locking bar, 2,179,307 11/ 1939 SYWeft 2- X (g) and means retaining said locking bar in said posi- 2,428,322 9/ 1947 Robertson et al 339198 tion on said support, said retaining means comprising 2,530,548 11/1950 Stanley 317119 means impeding release of said locking bar by access 2,738,444 3/1956 Casey 317- 1'19 from the front of said support. 65 2,803,476 8/1957 Ivanhoe 292-80 9. An electric control device panel assembly compris- 2 333 537 4/1959 DOrfman et 1 317 119 ingr 3,015,795 1/1962 Meacham 33991 X an enclosure contamlng a support, 3,089,063 5/1963 Middendorf et a1. 317 119 (b) at least lZWO electr cal bllS b511 5 supported 111 spaced 3,1,1190S1 1/19 4 Norden 317 119 apart insulated relation on 531d upp t, Edmunds (c) at least one electrical control device, said control device comprising an insulating body having opposed end portions,

((1) a resilient locking member carried by said control device at each of said end portions,

ROBERT K. SCI-IAEFER, Acting Primaly Examiner.

JOHN P. WILDMAN, LARAMIE E. ASKIN, E. JAMES SAX, Examiners. 

1. AN ELECTRIC CONTROL DEVICE PANEL ASSEMBLY COMPRISING: (A) A GENERALLY PLANAR SUPPORT HAVING A BACK SURFACE AND A FRONT SURFACE, (B) AT LEAST ONE ELECTRICAL BUS BAR CONDUCTOR SUPPORTED ON SAID FRONT SURFACE OF SAID SUPPORT, (C) A PLURALITY OF ELECTRIC CIRCUIT CONTROL DEVICES SUPPORTED IN MOUNTED POSITION ON SAID FRONT SURFACE OF SAID SUPPORT AND EACH ELECTRICALLY CONNECTED TO AT LEAST ONE OF SAID BUS BARS. (D) A LOCKING BAR RELEASABLY MOUNTED IN A FIXED POSITION ON SAID FRONT SURFACE OF SAID SUPPORT BY RETAINING MEANS, SAID RETAINING MEANS COMPRISING MEANS IMPEDING RELEASE ON SAID LOCKING BAR BY ACCESS FROM THE FRONT SIDE OF SAID SUPPORT, (E) INTERENGAGING MEANS CARRIED BY EACH OF SAID DEVICES AND SAID LOCKING BAR, (F) SAID INTERENGAGING MEANS COMPRISING MEANS PREVENTING REMOVAL OF SAID DEVICES FROM SAID SUPPORT WHILE SAID LOCKING BAR IN SAID FIXED POSITION BUT NOT PREVENTING INSERTION OF SAID DEVICES INTO SAID MOUNTED POSITION WHILE SAID LOCKING BAR IS IN SAID FIXED POSITION. 